title: Preliminary assessment of the tissue effects of a 1.44-micron laser via direct fiber contact on soft tissue.
abstract: OBJECTIVE
  A new pulsed near-infrared laser was developed for incision of soft tissues. This article presents a preliminary investigation of the 1.44-micron laser.
  
  
  METHODS
  A prototype laser was used with a cleaved 600-micron quartz fiber (1.44 microns, 5-30 Hz, 30 W max.). Standardized 5-cm incisions were made on skin, striated muscle, and liver in anesthetized New Zealand White rabbits. The animals were euthanized and the tissues were immediately harvested, and histologic examination completed after hematoxylin and eosin (HE) staining. The acute zone of coagulation was measured. A wound healing study was conducted on anesthetized NZW rabbits. The hind leg muscle was exposed and four, 5-cm incisions were made using the laser (0.5 J, 25 Hz) and four incisions were made with an electrosurgical unit on coagulating current (25 W). The incisions were marked and the overlying skin reapproximated. One rabbit was euthanized on day 11 and one on day 21. The wounds were exposed and excised for histology.
  
  
  RESULTS
  The acute zone of injury was 1160 +/- 120 microns to 1250 +/- 110 microns for skin; 70 +/- 20 microns to 400 +/- 280 microns for muscle, and 660 +/- 120 microns to 1930 +/- 300 microns for liver. The chronic study demonstrated less inflammation in the laser wounds on day 11 and a chronic inflammatory response on day 21. No gross differences in healing were noted.
  
  
  CONCLUSIONS
  The 1.44 microns laser wavelength interacts with tissues in a manner that is substantially equivalent to the holmium laser (2.1 microns). Further studies of the 1.44 microns laser and delivery system development are warranted.
authors.affiliation: Rochester General Hospital Laser Center, New York 14621, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Lanzafame
authors.forename: J
authors.initials: J
authors.lastname: Naim
mesh_terms: D000818:Animals; D062109:Dermatologic Surgical Procedures; D006695:Holmium; D007259:Infrared Rays; D053685:Laser Therapy / Q000009:adverse effects*; D007834:Lasers / Q000009:adverse effects; D008099:Liver / Q000528:radiation effects* / Q000601:surgery; D009132:Muscles / Q000528:radiation effects* / Q000601:surgery; D011817:Rabbits; D012867:Skin / Q000528:radiation effects*; D017695:Soft Tissue Injuries / Q000209:etiology; D014945:Wound Healing / Q000502:physiology*
chemical_list: D006695:Holmium